62 research outputs found
Removal of Triphenylmethane Dyes by Bacterial Consortium
A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50âmg/L) and malachite green (50âmg/L) dyes within 24âh. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2âh. The rate of chemical oxygen demand (COD) removal increases after 24âh, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes
Effects of industrial ironing on mechanical and dimensional properties of cotton,wool and polyester fabrics
The influence of industrial ironing cycle on low-stress mechanical properties and on dimensional changes in three selected weave fabrics has been studied. The experimental results are statistically analyzed using ANOVA. It is observed that the compressional properties measured by FAST system are the most influenced by the process of ironing. Cotton and wool fabrics show much variation in mechanical and dimensional changes compared to polyester fabric
F015 Role des fibroblastes cardiaques dans la tolĂ©rance des cardiomyocytes Ă lâischĂ©mie reperfusion
ObjectifLes fibroblastes cardiaques sont la population cellulaire majoritaire du tissu cardiaque. Leurs possibles implications au cours de la sĂ©quence ischĂ©mie-reperfusion nâa jamais Ă©tĂ© Ă©tudiĂ©e. Le prĂ©sent travail a donc pour but de dĂ©terminer si les fibroblastes sont impliquĂ©s dans une modulation de la cardioprotection.MatĂ©riel et MĂ©thodesNous avons utilisĂ© dans cette Ă©tude un modĂšle de cardiomyocytes de rats nouveau-nĂ©s soumis Ă une sĂ©quence dâischĂ©mie-reperfusion simulĂ©es. Les cellules ont Ă©tĂ© isolĂ©es Ă partir de ventricules de rats nouveau nĂ©s. Les myocytes cardiaques ont Ă©tĂ© purifiĂ©s par attachements diffĂ©rentiels puis cultivĂ©s en prĂ©sence dâun milieu de culture supplĂ©mentĂ© en cytosine arabinoside (Ara C, 10ÎŒm). Les cardiomyocytes et les fibroblastes ont Ă©tĂ© cultivĂ©s sĂ©parĂ©ment puis placĂ©s en contact direct (cultures mixtes) ou indirect (insert). Ces co-cultures ont subi une ischĂ©mie de 3H en absence de nutriments et dâO2 suivie dâune reperfusion de 20H en prĂ©sence de nutriments et dâO2. Des tests de viabilitĂ© (test MTT) et de mortalitĂ© cellulaire (dosage de lâactivitĂ© LDH et Troponine I) ont Ă©tĂ© effectuĂ©s Ă la fin de la reperfusion.RĂ©sultatsNous avons montrĂ© quâil Ă©tait possible de simuler des sĂ©quences dâischĂ©mie reperfusion et dâinduire une souffrance cellulaire dĂ©tectable pour une durĂ©e dâischĂ©mie de 3H et de reperfusion de 20H. Dans les cultures mixtes (cardiomyocytes + fibroblastes), les tests MTT et LDH ont montrĂ© une amĂ©lioration de la viabilitĂ© cellulaire globale en comparaison avec la viabilitĂ© spĂ©cifique de chaque type cellulaire seul. Pour les cultures placĂ©es en insert, les tests MTT et Troponine I ont montrĂ© une amĂ©lioration de la viabilitĂ© des cardiomyocytes en prĂ©sence des fibroblastes (p<0.001).ConclusionsNos rĂ©sultats indiquent que les fibroblastes cardiaques semblent ĂȘtre impliquĂ©s dans une modulation de la cardioprotection lors de lâischĂ©mie reperfusion. Cette modulation passe au moins en partie par des mĂ©canismes de type paracrine et elle est dĂ©pendante de la quantitĂ© de fibroblastes en co-culture avec les cardiomyocytes
D010 Mesenchymal stem cells protect cardiomyocytes from reperfusion injury through a paracrine activation of the PI3 kinase pathway
ObjectivesPrevious data suggest that implantation of mesenchymal stem cells (MSCs) improves heart function after myocardial infarction. We investigated whether protection afforded by MSCs might involve a paracrine activation of the PI3 kinase pathway in reperfused cardiomyocytes.MethodMSCs and neonatal rat cardiomyocytes (NRCs) were isolated and cultured separately. NRCs (2.106) were subjected to 5 hours of ischemia followed by 16 hours of reperfusion. At the time of reperfusion, NRCs (n=8-14/group) received either fresh medium (control group), or the following treatments: MSCs (2.105 MSCs in fresh medium), conditioned SN (MSCs supernatant alone (i.e. without MSCs) obtained after 8 hours of serum deprived culture), [conditioned SN + LY294002] (15 microM of LY294002 a specifi c inhibitor of PI3K), [conditioned SN + Wortmannin] (100 nM of wortmannin, a non specifi c inhibitor of PI3K), or CsA (200 nM in fresh medium) a potent inhibitor of the mitochondrial permeability transition pore. Cell death was assessed by LDH release in NRCs supernatant at the end of reperfusion.ResultsAs expected, LDH activity was dramatically reduced by CsA, averaging 4 % of control values. LDH activity was signifi cantly reduced by MSCs alone and by conditioned SN, averaging 29 % and 12 % of control value, respectively. Both LY294002 and wortmannin signifi cantly attenuated conditioned SN induced protection.Conclusionour data suggest that MSCs can protect NRCs from reperfusion injury through a paracrine activation of the PI3K pathway
The cientificWorldJOURNAL Research Article Removal of Triphenylmethane Dyes by Bacterial Consortium
A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable colorremoval capability against crystal violet (50 mg/L) and malachite green (50 mg/L) dyes within 24 h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2 h. The rate of chemical oxygen demand (COD) removal increases after 24 h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes
Population Structure of Pseudomonas aeruginosa from Five Mediterranean Countries: Evidence for Frequent Recombination and Epidemic Occurrence of CC235
Several studies in recent years have provided evidence that Pseudomonas aeruginosa has a non-clonal population structure punctuated by highly successful epidemic clones or clonal complexes. The role of recombination in the diversification of P. aeruginosa clones has been suggested, but not yet demonstrated using multi-locus sequence typing (MLST). Isolates of P. aeruginosa from five Mediterranean countries (nâ=â141) were subjected to pulsed-field gel electrophoresis (PFGE), serotyping and PCR targeting the virulence genes exoS and exoU. The occurrence of multi-resistance (â„3 antipseudomonal drugs) was analyzed with disk diffusion according to EUCAST. MLST was performed on a subset of strains (nâ=â110) most of them had a distinct PFGE variant. MLST data were analyzed with Bionumerics 6.0, using minimal spanning tree (MST) as well as eBURST. Measurement of clonality was assessed by the standardized index of association (IAS). Evidence of recombination was estimated by ClonalFrame as well as SplitsTree4.0. The MST analysis connected 70 sequence types, among which ST235 was by far the most common. ST235 was very frequently associated with the O11 serotype, and frequently displayed multi-resistance and the virulence genotype exoSâ/exoU+. ClonalFrame linked several groups previously identified by eBURST and MST, and provided insight to the evolutionary events occurring in the population; the recombination/mutation ratio was found to be 8.4. A Neighbor-Net analysis based on the concatenated sequences revealed a complex network, providing evidence of frequent recombination. The index of association when all the strains were considered indicated a freely recombining population. P. aeruginosa isolates from the Mediterranean countries display an epidemic population structure, particularly dominated by ST235-O11, which has earlier also been coupled to the spread of Ă-lactamases in many countries
SynthĂšse dâamido-calix[4]arĂšnes pour la complexation et la nanochimie
Dans une premiĂšre partie, la synthĂšse de dĂ©rivĂ©s amido-calix[4]arĂšnes a Ă©tĂ© dĂ©crite au cours de ce travail. LâĂ©tude de lâextraction solide-liquide de sels de picrates des cations alcalins, alcalino-terreux, des mĂ©taux de transition et des mĂ©taux lourds a Ă©tĂ© rĂ©alisĂ©e par spectroscopie de RMN du proton. La stoechiomĂ©trie des complexes formĂ©s est dĂ©terminĂ©e en calculant le rapport dâintĂ©gration entre le signal des deux protons du picrate et ceux du ligand. Cette Ă©tude montre la complexation des cations, des anions et dans certains cas de la paire dâions par nos dĂ©rivĂ©s. La stabilitĂ© des complexes formĂ©s a Ă©tĂ© suivie par Ă©tude spectrophotomĂ©trique dans lâUV et les constantes de stabilitĂ© des complexes ainsi formĂ©s ont Ă©tĂ© dĂ©terminĂ©es en utilisant le programme de calcul âLetagropâ.
Dans une seconde partie, la sĂ©lectivitĂ©-1,3 des rĂ©actions de dialkylation des calix[4]arĂšnes, et des rĂ©actions dâamidation nous ont permis de synthĂ©tiser des molĂ©cules hyperbranchĂ©es et des dendrimĂšres constituĂ©s de calix[4]arĂšnes. Nous avons en particulier synthĂ©tisĂ© la premiĂšre et la seconde gĂ©nĂ©ration de ces calix-dendrimĂšres par synthĂšse convergente et divergente.In a first part, we describe the synthesis of amido-calix[4]arenes supporting imidazole moieties as molecular receptors. Then, we have studied the extraction, by these receptors, of solid metal picrate salts of alkaline, alkaline-earth, transition metals and heavy metals with the 1H NMR spectrometry technique. The stoichiometry of the complexes was determined as the ratio between the integration of the two protons of the picrate and those of the ligands. This study also showed in some cases the concomitant complexation of cations and anions. The stability of the complexes was determined by UV complexation studies. The constants of stability were determined using the âLetagropâ program.
In a second part, the 1,3-selectivity of dialkylation reactions of calix[4]arenes and reactions of amidation allowed us to prepare hyperbranched molecules and dendrimers. In particular, we have prepared the first and second generations of calix-dendrimers by the divergent and convergent methods
Effects of industrial ironing on mechanical and dimensional properties of cotton, wool and polyester fabrics
167-172<span style="font-size:11.0pt;font-family:
" times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">The influence of industrial ironing cycle on low-stress mechanical
properties and on dimensional changes in three selected weave fabrics has been
studied. The experimental results are statistically analyzed using ANOVA. It is
observed that the compressional properties measured by FAST system are the most
influenced by the process of ironing. Cotton and wool fabrics show much
variation in mechanical and dimensional changes compared to polyester fabric.</span
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